Refrigeration



July 12, 1932 SELLMAN 1,867,181

REFRIGERATION Filed March 11, 1929 Patented July 12, 1932 UNITED s'rAres m-aaur OFFICE FOLKE EMIL SELLKAN, 01 WHITE PLAINS, NEW YORK, ASSIGNOB, BY MESN'E ASSIGN- MEN'IS, TO ELECTROLUX SERVE-L GORIPOBATION, NEW YORK, N. Y., A CORPORA- REFRIGERATION Application filed .llarch 11, 1929. Serial No. 846,180.

My invention has to do with the refrigcrating art and is more particularly related to refrigerating apparatus of the absorption type and still more particularly pertains to 5 generators or boilers making up a part of such apparatus.

In absorption refrigeratin apparatus, especially of the continuous y acting type wherein an inert gas is em loyed to obtain equality of pressure throug out, it has been found advantageous to place the generator in a substantially horizontal position in order to conserve space in a vertical direction and for adapting the apparatus to a cabinet. The generator is normally heated by a gas burner which projects a flame into a flue which has in the past extended centrally through the generator. The heat necessarily impinges more against the upper part of the flue than it does against the lower part and hence the former is heatedmore than the latter'. Furthermore, the upper part of the generator is not filled with liquid but this space is occupied by a gas or vapor which has been driven from so ution by the action of the heat. When it so happens, as it may in the known type generator, that the space occupied b this gas or vaporis suflicient to force the 11 uid level down below the upper part of the ue, this part, which receives the greatest heat from the flame, is not in contact with liquid and therefore is greatly overheated. This overheating is o viously detrimental to the." material of the flue and if.

as continued for a suflicient length of time might conceivably destroy the flue and allow the contents of the generator and other parts of the system to escape.

It is the purpose and ob ect of my invention to so construct the generator that the ossibility of the flue becoming uncovered y the liquid is reduced to a minimum and under all ordinary operating conditions done away with entirely. This is accom lished by locatingathe flue not centrally wit in the generator ut in the lower part thereof so that a less amount of liqui will serve to completely cover it. Another advantage of my invention of W equal importance is that a greater disengaging surface of the liquid is thereby obtained because in a horizontal cylindrical generator, the nearer the surface of the liquid is to the center of the generator, the greater will be this free surface. My inventlon allows the surface to fall lower than in the known type generator without uncovering the flue. In the known type, when the liquid surface fell to near the center of the generator even the advantage of an increased disengaging surface was not obtained as the presence of the flue in this region reduced the liquid surface. Hence, my invention realizes the combined advantages of a maximum disengaging surface and a fine always covered by liquid.

My invention is of particular importance in connection with a type of thermo-siphon in which a tube projects downwardly into the generator. In known generators of the horizontal type combined with this ty e of thermo-siphon, the tube has been p seed with its lower end below the top of the flue. In order to obviate any possibility that the level of liquid, by bein forced down to the bottomo this tube, wil uncover afpart of the flue, I prefer to arrange the top 0 the flue below the bottom of the thermosiphon tube.

Additional objects and advantages will appear from a consideration of the followmg description read in conjunction with the accompanying drawing on which Fig. 1 is an elevational drawing, partially in cross-section, showing my invention embogied in a preferred form of apparatus an Fig. 2 is an end view of the generator shown in Fig. 1.

Referring to the drawing, reference character 10 indicates a generator placed in a substantially horizontal position. Generator 10 comprises an outer cylindrical shell 11 through which lon 'tudinally extends a cylindrical flue 12. ue 12 is not placed centrally with respect to the generator but is located in the lower ortion thereof asis clearly shown in both igs. 1 and 2, the centerline of the flue being below the centerline of the shell. A gas burner 13 isarranged to project a flame into one end of the flue. In place of the burner an electric heating element or any other suitable source of heat may be placed in the flue.

Generator 10 is divided by a partition 14 into a smaller chamber 15 and a larger chamber 16. Communicating with the upper part of chamber 15 is a conduit 17 of comparatively large cross-section. Conduit 17 extends for some distance substantially parallel to the generator and thence vertically upwards and terminates within the upper part of a'rectifier jacket 18.

Aflixed to the upper part of chamber 16 is a vapor dome l9. Projecting through the top of dome 19 is a thermo-siphon conduit 20, the lower end of which terminates within chamber 16 and is provided with one or more holes '9. The upper end of conduit 20 communicates with conduit 17 at a point some distance above the generator. The lower end of conduit 20 is above the to of flue 12.

Posited within conduit 1 above conduit 20 and below jacket 18 is a number of battling disks 21. Adjacent disks are positioned so that their apertures are not in alignment so that vapor passing therethrough must travel in a somewhat tortuous path. A series of bafliing disks 25, which are preferably similar to disks 21, is posited within that portion of conduit 17 which is surrounded by jacket 18.

A conduit 26 communicates with the upper part of rectifier jacket 18, extends in a gen- ,erally horizontal direction, forming a loop,

and thence extends downwardly and communicates with a conduit which, below the point of communication is indicated by reference character 27, and above by reference character 28. A portion of conduit 26 is in heat exchange relation with a cooling water conduit 29 and constitutes a condenser 24. These two conduits are preferably welded or soldered together in or er to obtain a good heat transfer therebetween.

Conduit 27, which may be referred to as a liquid conduit in contradistinction to conduit 28, which is in actuality a continuation of conduit 27 but is intended only for the passage of extends downwardly from conduit 26, is formed in a full loop 30 and communicates with the lower part of jacket 18. A continuation of cooling water conduit 29 or other suitable container for cooling water is brought into heat exchange relation as by welding or soldering, with a portion of conduit 27 at and above loop 30.

Conduit 28 extends upwardly for some distance and thence downwardly and communicates with a gas space of the apparatus as will be explained.

A conduit 32 communicates with the central part of jacket 18. Conduit 32 extends within a larger conduit 33 and opens into the upper part of an evaporator 34. The evaporator is placed within the compartment to be cooled, a portion of a wall of which is formed by plate 35. Evaporator 34 comprises a closed cylindrical shell within which 1s laced a series of disks 36 which are provide with apertures 37 surrounded by raised rims 38. A conduit 39 connects the lower part of evaporator 34 with the interior of a cylindrical member 40 which forms the inner passage of a gas heat exchanger. Within member 40 is a series of bafliing disks formed to give a tortuous flow to gas within the same.

Arranged concentricall around the greater part of member 40 is an outer cylindrical member 43. A wire 44, having a diameter equal to the annular space between members 40 and 43, is wound in the form of a spiral in this space and serves to cause fluid passing therethrough to travel in a spiral course.

A conduit 46 connnects the lower end of member 40 with the lower part of an absorber 47. Absorber 47 comprises a closed cylindrical shell in which are ositioned disks 48 which may be similar to isks 36 in evaporator 34. A conduit 49 connects the upper part of the absorber with the annular space' of the gas heat exchanger. Conduit 33 connects the upper part of the annular space with the upper part of evaporator 34. A cooling water conduit 50 is placed around the outside of absorber 47 and is preferably welded thereto in order to obtain good heat transfer. Cooling water conduit 50 extends upwardly from the absorber and conduit 29 is an extension thereof.

A conduit 52 communicates with the lower part of absorber 47 and extends downwardly to an outer member 53 of a liquid heat exchanger. A conduit 54 connects the other end of member 53 with the lower part of the larger chamber 16 of generator 10. A conduit 55 communicates with the lower part of the smaller chamber 15 of the generator, extends within outer member 53 and thence u wardly to the upper part of absorber 4 7. Conduit 55 is preferably brought in heat exchange relation with cooling water conduit 50 by welding to successive turns thereof.

The system of ap aratus contains a cooling agent, preferab y ammonia, an absorption liquid, preferably pure water, and an inert gas, preferably hydrogen.

The operation of the apparatus is substantially as follows: A solution consisting of ammonia dissolved in water is contained within compartments 15 and 16 of generator 10. The application of heat to this solution causes the formation of ammonia vapor. The vapor thus formed occupies space in the upper portion of chamber 16 and maintains the liquid level therein at some such position as is shown in Fig. 1. The exact osition is determined by the rate of gas evo ution and the size and arrangement of openings 9 in thermo-siphon conduit 20. By reason of the fact that the flue 12 is in the lower portion of the generator, these holes may be so arranged that the gas will occupy a greater space in the generator and there ore the liquid surface will be lower and\hence of greater extent. This larger disengagin surface renders the formation of gas less cult and increases the efliciency of the generator and hence of the apparatus as a whole. This advantage is obtained without the danger of the upper part of flue 12 becoming dry and hence overeated. Should the holes 9 become clogged or should'the generation of as become so rapid that the level of liqui falls to the lower open end of conduit 20, the flue tube will, nevertheless, not be uncovered and exposed to gas.

The vapor formed in chamber 16 passes therefrom throu h thermo-siphon conduit 20 and carries with it through this conduit small slugs of liquid, thus lifting the liquid to conduit 17. Vapor formed in chamber 15 passes therefrom upwardly through conduit 17 in counterflow to the liqpid passing downwardly therethrough. Con uit 17 has a bore of sufiicient size so that the ascending vapor will not carry along slugs of liquid, as is t e case in conduit 20, but can b'ubble freely th ough the liquid.

The vapor passes upwardly through conduit 17 and is rectified in its passage through disks 21 and 25. The dry ammonia gas passes from jacket 18 into conduit 26 where it is liquefied and the liquid passes through conduit 27 and loop 30 t0 the lower part of jacket 18. The liquid ammonia in jacket 18 serves to rectify the gas within conduit 17. The ammonia passes from jacket 18 through conduit 32 into evaporator 34.

The purpose of conduit 28 is to carry away from the condenser and rectifier any inert gas which may be entrained into the generator with absorption liquid coming from the absorber and passes up through conduit 17.

The liquid ammonia introduced into evaporator 34 through conduit 32 is brought into contact with the gas inert with respect to ammonia, preferably hydrogen, between which two substances there occurs mutual diffusion and the ammonia evaporates. The heat necessary for this evaporation is taken from the surroundings of the evaporator and thus refrigeration is produced.

The gaseous mixture of ammonia and hydrogen formed in the evaporator asses downwardly therethrough and throng conduit 39 to member 40 of the gas heat exchanger. The mixture passes downwardly through baflies 42 and through conduit 46 into the lower part of absorber 47. In the absorber the mixture comes into contact with water which contains relatively little ammonia in solution and which is introduced through conduit 55. This water absorbs the ammonia vapor while the hydrogen is not absorbed and passes from the upper part of the absorber, through conduit 49 to within member 48. Here it passes upwardly along the spiral path defined within member 43 by wire 44. In the I heat exchanger this hydrogen gas is precooled before entering the evaporator by the cold mixture of ammonia and hydrogen which has just left the evaporator. From the to of member 43 the hydrogen is conducte through conduit 33 to evaporator 34. This gas circulation between and through the evaporator and absorber is produced due to the fact that the specific weight of the ammonia-hydrogen mixture is greater than that of the relatively pure hydrogen and thus an unbalanced circulation prevails which results in the aforementioned condition.

A small amount of water va or leaves the absorber with the hydrogen an virtually all p of this is condensed within member "43. The

condensate thus formed may drain back into the absorber through conduit 49.

The strong solution of ammonia dissolved in water formed in absorber 47 passes therefrom by gravity through conduit 52, member 53 and conduit 54 to chamber 16 of generator 10. From here it is caused to circulate by thermo-siphon action as was previously explained, through conduits 20 and 17 to chamber 15. In both chambers 15 and 16 the ammonia is driven out of solution and the weak absorption liquid flows from chamber 15 through conduit 55 to the u per part of absorber 47. The circulation of liquid from chamber 15 to the absorber results from the fact that thermo-siphon conduit 20 discharges into conduit 17 at a point above the point of discharge of conduit 55 into the absorber.

While I have described a preferred, but more or less specific embodiment of my invention, it is to be understood that modifications thereof fall within its scope which is limited only by the appended claims.

What I claim is:

1. In an absorption refrigerating apparatus, a generator, a condenser, an evaporator, an absorber, means to circulate an absorption liquid between and through said generator and absorber comprising a thermo-siphon conduit extending into the generator and having an opening for communication with the generator, means to heat the liquid within said generator in order to drive oi! a gas to cause said thermo-siphon to operate, said heating means comprising a flue extendin longitudinally through said generator an locatedwithin the lower part of said generator in order that the flue will be covered with the liquid within the generator. and means for heating said flue, the top of said flue being below said opening.

2. In an absorption refrigerating apparatus, a generator, a condenser, an evaporator,

an absorber, means to circulate an absorption liquid between and through said generator and absorber comprising a thermo-siphon conduit extending into the generator and 5 having an opening for communication with the generator, means to drive ofi a gas from the li uid in said generator in order to cause said t ermo-siphon to operate comprising a source of heat, a flue extending longitudinalm 1 through said generator, means to heat said tile and means allowing a maximum free surface of the liquid within said generator comprising the location of said flue in the lower pgrt of said generator, the top of said flue ing below said opening. 3. Absorption refrigerating apparatus comprising a generator, an evaporator, an ab: sorber, means to circulate an absorption liquid between and through the generator and 99 absorber comprising a thermo-siphon tube extending downwardly into the generator, a flue extending longitudinally through the generator located within the lower part of the said generator, the top of the flue being be- 95 low the bottom of the thermo-siphon tube and heating means for said flue.

4. In an absorption refrigerating apparatus, a generator, a condenser, an evaporator, an absorber, said generator comprising a sub- 30 stantially horizontal c lindrical shell, a. flue extending longitudina y therethrough and located in the lower part thereof, a partition dividing said generator into a smaller chamber and a larger chamber, means to circulate absorption liquid between and through said generator and absorber comprising a thermosiphon conduit, the lower end of said conduit extending within said larger chamber a conduit connecting the other end of said t ermosiphon conduit with said smaller chamber, a conduit connecting said smaller chamber with said absorber and a conduit connectin said absorber with said larger chamber, and means for heatin said flue in order to expel gas from liquid within said generator to cause said thermo-siphon to operate, the top of said flue being below the bottom of said thermosiphon conduit.

In testimony whereof I have aflixed my signature.

FOLKE EMIL SELLMAN.

DISCLAIMER 1,867,18L-F0lke- Emil Sellman White Plains, N. Y. Rnrmoana'rxon. Patent dated July 12, 1932. bisclaimer filed August 27, 1935, by the assignee, E'lectrolm: Servel Corporation. J Hereby disolaims each and all of claims numbered 1 2, 3 in said specification except as said claims define a refrigerating apparatus including a generator having apartition dividing said generator into at east two chambers.

Oficial Gazette September 24, 1936.]

an absorber, means to circulate an absorption liquid between and through said generator and absorber comprising a thermo-siphon conduit extending into the generator and 5 having an opening for communication with the generator, means to drive ofi a gas from the li uid in said generator in order to cause said t ermo-siphon to operate comprising a source of heat, a flue extending longitudinalm 1 through said generator, means to heat said tile and means allowing a maximum free surface of the liquid within said generator comprising the location of said flue in the lower pgrt of said generator, the top of said flue ing below said opening. 3. Absorption refrigerating apparatus comprising a generator, an evaporator, an ab: sorber, means to circulate an absorption liquid between and through the generator and 99 absorber comprising a thermo-siphon tube extending downwardly into the generator, a flue extending longitudinally through the generator located within the lower part of the said generator, the top of the flue being be- 95 low the bottom of the thermo-siphon tube and heating means for said flue.

4. In an absorption refrigerating apparatus, a generator, a condenser, an evaporator, an absorber, said generator comprising a sub- 30 stantially horizontal c lindrical shell, a. flue extending longitudina y therethrough and located in the lower part thereof, a partition dividing said generator into a smaller chamber and a larger chamber, means to circulate absorption liquid between and through said generator and absorber comprising a thermosiphon conduit, the lower end of said conduit extending within said larger chamber a conduit connecting the other end of said t ermosiphon conduit with said smaller chamber, a conduit connecting said smaller chamber with said absorber and a conduit connectin said absorber with said larger chamber, and means for heatin said flue in order to expel gas from liquid within said generator to cause said thermo-siphon to operate, the top of said flue being below the bottom of said thermosiphon conduit.

In testimony whereof I have aflixed my signature.

FOLKE EMIL SELLMAN.

DISCLAIMER 1,867,18L-F0lke- Emil Sellman White Plains, N. Y. Rnrmoana'rxon. Patent dated July 12, 1932. bisclaimer filed August 27, 1935, by the assignee, E'lectrolm: Servel Corporation. J Hereby disolaims each and all of claims numbered 1 2, 3 in said specification except as said claims define a refrigerating apparatus including a generator having apartition dividing said generator into at east two chambers.

Oficial Gazette September 24, 1936.] 

